In the Garden:
Southern California Coastal & Inland Valleys
Cauliflower "ricing" occurs when it's overmature, and purple coloring results after too much exposure to the sun.
Common Problems With Brassicas
Planning to grow Brassica family members -- broccoli, Brussels sprouts, cabbage, cauliflower, kale, or kohlrabi? Here are some problems you may run into, and ways to prevent or lessen them next time around:
Symptom: Plants wilt, fall over, and have tunneled stems; roots have been eaten.
Problem: Cabbage root maggot
Solution: Plant seeds early in the fall so they develop into large, vigorous transplants that overwinter well and can be harvested early in the spring. Protect seedlings with a cheesecloth cover to prevent the adult black flies from laying their eggs in the surrounding soil. Place collars around transplants. Dust with a mixture of lime and wood ashes or with diatomaceous earth, but be certain to purchase only the type sold for garden use, not the one labeled for swimming pool use. Interplant with mint, rosemary, sage, and tomato.
Symptom: Plants are stunted, leaves turn yellow and wilt, and roots are misshapen and enlarged with club-shaped knots that rot and become slimy.
Problem: Club root
Solution: Plant healthy transplants of a resistant variety. Rotate crops. Maintain soil pH above 7 by sprinkling wood ashes around the base of the plant.
Symptom: Foliage edges appear burnt.
Problem: Water stress and calcium deficiency, especially on dry soils which are acidic or high in potassium
Solution: Provide plants with sufficient water to maintain steady growth. Calcium is not available to plants at a low pH. Dolomitic limestone (for gardens, not pools) is a good source of lime and magnesium. The finer the grade of the limestone, the faster it can break down in the soil, raise the pH, and enable the calcium to be utilized. Incorporate bone meal, gypsum, and plant residues. Rotate crops.
Symptom: Cabbage or Brussels sprouts heads suddenly split when they have grown fast.
Problem: Too much fertilizer or water after a prolonged dry period, making the inner leaves grow faster than the outer leaves
Solution: Don't allow the soil to get too dry. Apply water slowly at first after a dry period.
Symptom: Cauliflower heads look cracked and may have leaves growing through the head.
Problem: Overmature, fertilized with too much nitrogen, or extremely hot or dry weather
Solution: Don't let the soil dry out. Plant varieties with shorter growing period so they're mature before the weather gets too hot.
Symptom: Cauliflower forms heads when the plants are still small.
Problem: Weather got too warm before there was sufficient plant development.
Solution: Plant earlier in the season so that plants can mature before warm temperatures trigger heading.
Symptom: Cauliflower heads are only the size of buttons.
Problem: Nitrogen deficiency or poor drainage
Solution: Apply a nitrogen fertilizer. Aerate the soil to improve drainage.
Symptom: Cauliflower heads are brown, stunted, deformed, hollow-stemmed, or with pithy cores.
Problem: Boron deficiency
Solution: Apply a complete fertilizer (nitrogen, phosphorus, and potassium) that also contains micronutrients.
Symptom: Cauliflower heads turn yellow or brown.
Problem: Sunburn or frost
Solution: Plant cauliflower so that they mature before the first expected frost. Whether grown in fall or spring, tie the outer leaves up around the head when it's about 3 inches across, so sunlight can't reach the white curd. Harvest it from four to seven days later.
Symptom: Foliage is deformed, wilted, and has whitish or yellowish spotting.
Problem: Harlequin bug
Solution: Handpick and destroy adults and egg clusters. Control nearby weeds. For severe infestations, spray with pyrethrum, rotenone, or sabadilla. However, rotenone and sabadilla kill beneficial insects too, so use them only for major infestations.
Symptom: Foliage has large ragged holes and green caterpillars are present.
Problem: Cabbage worms
Solution: Handpick and destroy worms and egg clusters. Spray with Bt (Dipel, Thuricide, Biotrol) every seven to ten days. The adult white butterfly moths will be deterred by planting hyssop, pennyroyal, rosemary, sage, thyme, and wormwood. Spray a diluted solution of ground leaves of these plants onto the crops, reapplying after rains or overhead irrigation. Spread cheesecloth over the crops and anchor it at the soil level to keep the moths from reaching the crops to lay their eggs.
I hope these tips help keep your veggies healthy and productive.
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